Multi-touch

1. Advantages

1.1. convenient

1.2. funny

1.3. the screen has finger print

1.4. Fast command selection

2. limitations/disadvantages

2.1. easy to break down as we touch it a lot

2.2. Possible arm fatigue

2.3. Difficult to select small items

3. technology

3.1. LLP（laser light plane）

3.2. FTIR（Frustrated Total Internal Reflection）

3.3. ToughtLight

3.4. Optical Touch

3.4.1. New node

4. Definition

4.1. multi-touch refers to a touch sensing surface's (trackpad or touchscreen) ability to recognize the presence of two or more points of contact with the surface.

5. Implementations

5.1. mobile devices

5.2. tablets

5.3. touchtables

5.4. walls